Comparative Evaluation of Cytologic and Cell Block Results in Received Fluids in Rasool Akram Hospital, 2003

The importance of exact diagnosis of diseases and prevention of complications caused by them is evident to everyone. One of the preventive methods is early detection of diseases. Cytologic examination is a useful and effective method among all. Recognition of early changes of cell morphology could perhaps help us diagnose diseases and manage them before clinical manifestations appear. The present study compared the results of cytology with cell block findings to distinguish if cell block findings could complement cytologic results. 300 patients referred to the hospital in 2003 underwent aspiration and lavage. Cytologic and cell block slides were obtained from specimens. Thereafter, specimens were divided into 5 categories: 1- inflammatory 2- malignant 3- suspicious 4- negative for malignancy 5- lymphocytic rich. The results of cytology and cell block were compared. Among obtained fluids, pleural and peritoneal specimens were the most frequent, and bronchoalveolar lavage and thyroid aspiration were next. Regarding findings, 53% of cytologic results and 54.2% of cell back ones were negative for malignancy. Chronic inflammation was found to be 31.9% and 21.5% in cytology and cell block respectively. The percentage of suspicious specimens was 3% for cytology and 2% for cell block. Malignancy constituted 4% of all both in cytology and cell block. Other specimens including bloody, unsatisfactory and insufficient were excluded from the report. In addition, malignant samples were documented by biopsy which was considered as gold standard pathway showing 54.5% sensitivity and 98.5% specificity in cytology(P=0.000) and 70% sensitivity and 97.8% specificity in cell block. PPV(Positive Predictive Value) and NPV(Negative Predictive Value) were 60% and 98.1% for cytology respectively, and cell block showed PPV of 99% and NPV of 98.9%. Comparing cytology and cell block with biopsy specimens, the following results were obtained. Concerning pleural effusion, specificity and sensitivity of cytology were 99% and 33.3% respectively(P=0.000). In cell block, sensitivity and specificity were 100%(P=0.002). Positive predictive value(PPV) and negative predictive value(NPV) in cytology of pleural effusion were 50% and 98% and in cell block 40% and 100% respectively. With regard to peritoneal fluid, the results of biopsy specimens were compared with those of cytology and cell block. In cytology, sensitivity and specificity were 71.4% and 98.9% respectively(P=0.000). Positive predictive value(PPV) and negative predictive value(NPV) in cytology were 83.3% and 97.9%, and in cell block 83.3% and 97.9% respectively. Ultimately, to find out correspondence between cell block and cytology, we used test of agreement. Kappa was 0.977, which showed desirable conformity. Acceptable correspondence was found between cytology and cell block. However, specificity was higher than sensitivity in malignant reports in cytology. This could mean that positive results in cytology can be confirmed by biopsy. But low sensitivity indicates that some malignant cases may be ignored in cytology. Therefore, because of high rates of false negative in cases of malignancy, we can make use of complementary techniques such as cell block.